See post #31.
In my opinion the best inside home defense weapon is a 12 ga shotgun with a short barrel loaded with #1 shot. Around town I pack an Officer length 45ACP 1911. I have a large assortment of weapons from .17 HRM Revolver to a Barret 50BMG and a 75 caliber Brown Bess Musket. They are all fun to shoot, but there are only a few that I "train" with and the shotgun and the 45 are the ones I trust most.
Bottom line is the most effective round is the one you use, the one you are competent with.